Recently, wafers for semiconductors are getting larger and thinner and electronic parts are getting smaller and more precise, so that resin materials are required to have advanced functions. Silicone materials have good insulation property, flexibility, heat resistance and transparency and, therefore, is broadly used as resin materials for semiconductor devices and electronic parts.
Japanese Patent No. 3944734 discloses a polymeric compound having siloxane and bisphenol structures and a photo-curable resin composition comprising the polymeric compound. Japanese Patent No. 3949734 describes that the polymeric compound can be exposed with a light having a wide range of wavelengths to form a fine pattern which has high elasticity and good transparency and the cured coating obtained from a resin composition comprising the polymeric compound has good adhesiveness to a substrate, heat resistance, electric insulation and strength.
Japanese Patent Application Laid-Open No. 2008-184571 discloses a polymeric compound having a silphenylene skeleton which has repeating units represented by the following formula and the photo-curable resin composition comprising the polymeric compound.

wherein R1 to R4 are, independently of each other, a monovalent hydrocarbon group having 1 to 8 carbon atoms, m is an integer of 1 to 100, a is a positive number, b is 0 or a positive number, and a/(a+b) is not less than 0.5, but not larger than 1.0. X is a divalent organic group represented by the following formula.
Japanese Patent Application Laid-Open No. 2008-184571 further describes that the photo-curable composition comprising the polymeric compound forms a coating which has various good film properties and reliability as a protective layer.
A wire bonding method with metallic thin lines has been applied to connect a semiconductor chip and a substrate. However, semiconductor devices require high density and high integration, so that a flip-chip mounting method is being mainly used, where conductive projection called bump is formed on the semiconductor chip to directly connect an electrode on a substrate and the bump on the semiconductor chip. In the flip-chip mounting method, interstices between the semiconductor chip and the circuit substrate are sealed with an underfill material in order to improve the strength of the interface and reliability of the semiconductor device. A capillary underfill method is generally applied for the sealing with an underfill material. Japanese Patent Application Laid-Open No. 2007-217708 describes that the capillary underfill method where the underfill material is applied on the one side or plural faces of the chip to allow the underfill material to flow into interstices between a circuit substitute and a chip through a capillary phenomenon to fill there.
The capillary underfill method requires the steps (a) to (g) shown in FIG. 9. The steps will be explained below.
Step (a): A flux material (21) is applied on a circuit substrate (20).
Step (b): A semiconductor chip (22) provided with bumps (22a) is mounted on the circuit substrate (20).
Step (c): The semiconductor chip (22) is bonded to the circuit substrate (20) via the flux materials (21) to form bonding parts (23).
Step (d): The flux materials (21) are washed off.
Step (e): An underfill material (24) is applied on one side or plural faces of the semiconductor chip (22).
Step (f): The underfill material (24) is allowed to flow into interstices between the circuit substrate (20) and the semiconductor chip (22) through capillary phenomenon.
Step (g): The filled underfill material (24) is cured to encapsulate the semiconductor device.
As described above and shown in FIG. 9, the capillary underfill method comprises complicated steps and requires treatment of the wastewater from the washing. Further, the step (f) relies on the capillary phenomenon, so that the time for filling the material is long and, therefore, problems occurred sometimes in the productivity of a semiconductor device.
To solve the problems, Japanese Patent Application Laid-Open No. 2009-239138 discloses a method where a film having an adhesive layer of a resin composition comprising a cross-linkable resin, a compound having flux activity and a film-forming resin is applied on a functional face of a semiconductor chip. In this method, the film for a semiconductor device works as a flux and an encapsulating material, so that the semiconductor chip can be bonded to the circuit substrate without any flux material. Therefore, the aforesaid steps (a), (d), (e) and (f) are unnecessary, whereby the productivity for semiconductor devices is improved.